Beam selection in non-terrestrial networks

A method performed by a network node for connecting a wireless device to a second satellite in a non-terrestrial network (NTN), wherein the wireless device employs a first beamforming matrix for directing a radio beam from an antenna array of the wireless device to a first satellite, the method comprising, the method comprising:

• enabling the wireless device to perform a process comprising:
• i) determining an angular difference between a direction towards the first satellite and a direction towards the second satellite;
• ii) generating a rotation matrix using the determined angular difference between the direction towards the first satellite and the direction towards the second satellite to generate;
• iii) multiplying the first beamforming matrix with the rotation matrix to create a second beamforming matrix;
• and iv) using the second beamforming matrix to communicate with the second satellite, wherein
• the enabling comprises:
• transmitting to the wireless device ephemeris data of the first and the second satellite, thereby enabling the wireless device to determine the angular difference between the direction towards the first satellite and the direction towards the second satellite, and
• prior to determining the rotation matrix, the wireless device determines an orientation of the antenna array relative to the positions of the satellites.